Early Experience With QWIKMAP Software Technology and QWIKSTAR Ablation Catheter: An Interview With Jay Simonson, MD

Dr. Simonson's team is among the country's most experienced users of the CARTO XP EP Navigation and Ablation System and a pioneer with Biosense Webster, Inc.'s new QWIKMAP Software Technology and the QWIKSTAR Ablation Catheter. Dr. Simonson himself has extensive hands-on experience with the CARTO XP System, the NAVISTAR Catheter, QWIKMAP Technology and the QWIKSTAR Catheter. 

Biosense Webster, Inc.: What mapping system were you using before you got interested in rapid mapping technology?

Dr. Simonson: We've had the CARTO System in our lab for about 4 or 5 years now, using it with the NAVISTAR Catheter.

Why did you decide to adopt rapid mapping technology?

We're always looking for ways to do things faster and more effectively. The NAVISTAR Catheter is a one-point-at-a-time technology. With QWIKMAP Technology, we can obtain multiple points with each click. I also think it helps with creating the geometry of the chamber more quickly to get a better idea of the reaches of each chamber and to do a fuller map. These are the major reasons, the speed and accuracy.

The benefits of the speed were specifically what what did you think they would be, and did they turn out that way?

There are some instances where it has sped up the procedure. You still have to look at each point that you collect and make sure you agree with them and reject some that you don't. However, I think among the areas where we found the QWIKMAP Software to be helpful is specifically when we do atrial flutter ablation when you re looking to confirm a line of block to make sure that you completed that line. Where before I d have to grab six to ten points on the distal side of the line, I can now grab one or two points and be reasonably certain of a line of block. One of the areas where I've particularly liked the QWIKMAP Technology is in mapping of ventricular arrhythmias. We don t do as many of those as we do of atrial arrhythmias like atrial flutter, but still we do a fair number of them, and they can be more time-consuming. We ve had a couple of instances where QWIKMAP Technology has clearly helped us. One of my partners had a premature ventricular contraction (PVC) ablation, in which the PVC had a right ventricular outflow tract (RVOT) origin, and he was using QWIKMAP Technology. He started to get a few points and had about ten or twelve tip points with the accompanying shaft points, then he bumped the site of origin of PVC and they stopped occurring. When that happens to us, it is a very frustrating thing. However, since he had the QWIKMAP points, he was able to use some of the shaft points to identify the exact location of origin of the PVC, get his ablation catheter to that point, and ablate it there even though the patient wasn't having any PVCs at that time. Subsequently, the patient has had no recurrence. If we hadn't had those shaft points, we probably would have had to have the patient back for another procedure. Another example of the utility of QWIKMAP Technology occurred with a patient I had who was an ischemic ventricular tachycardia (VT) in the left ventricle. This patient had a couple of VT circuits. While we were mapping the VT, QWIKMAP Technology allowed us to quickly localize our circuit, direct us where to go and concentrate our map. We came retrograde across the aortic valve, and the area of interest was down toward the apex. By having the QWIKMAP shaft points, I was able to quickly see that the activation times near the aortic valve and near the base of the heart were quite late, so I was able to concentrate very quickly on the more apical septal region where this VT circuit originated. Before QWIKMAP Technology, I would have had to collect a fair number of points at the base of the heart to have excluded that region as being an essential part of the circuit. I still had to get a lot of points at the site of the circuit, but I didn t waste time looking at a distant site. The long shaft of the QWIKSTAR Catheter allowed me to see the region quickly. I was able to look at those shaft points and see that it would be a waste of time to be looking up there.

Before adopting QWIKMAP Technology with the QWIKSTAR Catheter from Biosense Webster, did you evaluate any other rapid mapping technologies?

I don t have personal experience with other technologies, but I've gone through a number of labs that are using them and have observed them in some detail.

Why did you choose QWIKMAP Technology?

I specifically chose the CARTO System using NAVISTAR Catheters to get the ultimate in both three-dimensional mapping and activation timing. Then QWIKMAP Software came along as a potential improvement upon that. Having the experience of the NAVISTAR Catheter, it was just natural to progress toward this. We did look at other rapid mapping technologies, but QWIKMAP has delivered all the capabilities that would have made the others attractive to us.

Once you adopted QWIKMAP Technology, how easy was the transition?

It was a bit of a transition, related to the nurses learning the new software. A single physician can t both map and run the CARTO System. You need to have a very good nurse doing the computer work while the physician maps. We've been training our nurses with the help of our excellent Biosense Webster representative, and we are to the point where our nurses can handle the majority of cases after about two months of experience.

Can you tell us about your learning curve?

I've been using the CARTO System for 5 years and I still find things that it does and new ways to use it, but I'm hesitant to call myself an expert. That s the power of it, though it can do so much, that you constantly discover new things it can help you do. In fact, you can start using it effectively pretty quickly. The same is true of the new QWIKMAP Technology. I would say it should only take the individual physician and nurse team about ten cases to be flying on their own.

What level of experience do you think it takes for an electrophysiologist to use QWIKMAP Technology effectively?

I think anybody who is doing electrophysiology on a regular basis, doing over 100 cases a year, could probably pick it up pretty quickly.

How have the quality and detail of QWIKMAP visualizations compared with the NAVISTAR visualizations you were getting before?

The quality has been much better for ventricular arrhythmias. I've had a little bit of a problem with some of the atrial arrhythmias because of having to go back and edit the shaft points. The ventricular activation is picked up as a bigger signal, and we have to go back and make sure we ve correctly identified the atrial signal.

Is that something you didn't have to do before because you didn't pick them up?

Exactly. You're grabbing more points and wanting to make sure that every point is tagged correctly. You want to visually check each one. Before you were grabbing one point at a time and editing it. Now you re grabbing seven points at a time and you want to edit them all. It is not difficult. It s just something you have to do.

In what kinds of cases have you used QWIKMAP Technology, and how has the technology contributed to diagnosing or treating those cases?

I have predominantly used it in atrial flutters, the PVC procedures in the RVOT, and also in left VTs. We have used it in a couple of atrial tachycardias. I have not been using it in my atrial fibrillation cases. The reason for that is the QWIKSTAR Catheter is a little bit stiffer than the NAVISTAR Catheter, and also because I have wanted a little bit more pinpoint mapping rather than using those shaft points. So I am still using my NAVISTAR Catheter for those. However, I can foresee using the QWIKMAP Technology in the future for tough procedures as my experience increases and the technology improves.

How has the QWIKSTAR Catheter changed the way you map atrial flutter, atrial fibrillation, atypical flutters, right ventricular outflow tract, and ischemic ventricular tachycardia?

It is all a matter of speed and confidence in localization.

In what ways does it give you more confidence in localization?

When you are trying to map an arrhythmia, you are trying to fine-tune the location of the earliest point. There s always a possibility that there s a point a little bit further away that is even better. By getting a larger number of points, you can definitely see that those other points are later and it helps direct you to the earliest point more quickly.

It sounds like you have been using it quite broadly. Is there any part of the heart you have NOT mapped with the QWIKMAP Technology?

We haven't gone onto the epicardium or into the pericardial space with it. However, we have covered all the inside chambers.

Have you found the shaft visualization capability useful?

That is another big advantage the ability to see the shaft location in real time. With QWIKMAP Technology, you get to see the whole shaft as well as the tip, and so you can see your angulation. Actually, I've been using less fluoro as a result of that, because you get a much better idea of how your catheter is bending and a better idea of where it is in three-dimensional space.

How much do you think the CARTO XP System with the NAVISTAR Catheter or QWIKMAP Technology reduces exposure to fluoroscopy, compared with conventional visualization methods?

In my experience, on a typical ablation case, it would probably cut down on fluoro use 25% to maybe as much as 50%.

How has QWIKMAP Technology benefited your practice?

I think QWIKMAP Technology sped things up a little bit. It has allowed us to take on perhaps tougher cases, or given us the confidence to take on tougher cases.

Do you feel in general that you are more productive with QWIKMAP Technology than you were before?

Yes.

What has QWIKMAP Technology done for your institution? Has it enhanced the hospital's prestige?

Yes, I think it has enhanced our prestige. We certainly are perceived in the community to be doing some of the toughest procedures and having the best technology. I think QWIKMAP Technology has also brought in more patients. We have a very efficient EP lab and we get things done pretty quickly.

What about productivity and efficiency? Do you think QWIKMAP Technology has affected these?

Well, we are doing more patients, so we are more productive. Efficiency is hard to measure. As we take on tougher cases and challenges, the procedure time increases. However, the efficiency of the standard flutter ablation or PVC ablation has greatly improved.